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CryptoHack

A free, fun platform for learning modern cryptography

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Learn By Doing

Learn about modern cryptography by solving a series of interactive puzzles and challenges. Get to know the ciphers and protocols that secure the digital world by breaking them.

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Level Up

Earn points by solving challenges. Finish categories to earn trophies and gain levels to track your progress. Can you reach the top of the scoreboard?

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Fresh Challenges

We are constantly creating new challenges to keep your crypto knowledge up to date. Expect exciting brainteasers and whole new categories as the site continues to grow.

New Challenges
ECLCG (HITCON CTF) CTF Archive 0
Sus (ImaginaryCTF) CTF Archive 0
Share (HITCON CTF) CTF Archive 0
Leet Universe (ImaginaryCTF (Daily)) CTF Archive 0
Hyper512 (HITCON CTF) CTF Archive 0
Weekly Top Users
#1 Madhu_Mitha 4400
#2 lydxn 3470
#3 Mahalakshmi 2080
#4 johnblack 1820
#5 kdm 1730
Recent Solves
Privacy-Enhanced Mail? sibo_guo
Fast Primes RosaTryp
Public Keys swnkuletz
Resisting Bruteforce cse13224zxiong19
Keyed Permutations cse13224zxiong19
Recent Solutions
Extended GCD m3h3d1 0
Chinese Remainder Theorem nim22 0
ECB Oracle Francesco 0
OR Proof sokoly 0
Quadratic Residues nim22 0

Level Up

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